This invention relates to electrical connectors used in nuclear power plants in the electric utility industry to electrically connect safety related reactor instrumentation with its associated mineral insulated sheathed cables. These electrical connectors are made up of a male and female portion which when connected together form a hermetic seal and electrically connect together numerous electric wire conductors. It is the normal practice to have these male and female electrical connector portions permanently attached by welding to the reactor instrumentation and the associated mineral insulated cable in the manufacture's factory at the time of initial manufacture. The purpose of the weld is to provide a hermetic seal to preclude ingress of moisture during normal operation and of containment spray during a loss of cooling accident and to provide structural support to maintain integrity of the cable and the connector during connection and torquing of the connector and also during seismic events. The electrical connectors are normally attached to the reactor instrumentation and the mineral insulated cables by using a component known as a backshell. This connector backshell is a hollow cylindrical component which is welded or threaded to the connector on one end and is welded to the instrument sheath or the sheath of the mineral insulated cable on the other end. Each of the male and female portions of the electrical connector have a cylindrical back end portion which is received within this cylindrical backshell.
Problems have been encountered in the field with these connectors typical of which problems are the breaking off of the connector from the reactor instrumentation or from the mineral insulated cable, electrical shorts or opens, bent or pushed in pins and cracked insulators.
The current options available to electric utilities experiencing these problems are to (1) scrap the instrument and/or cable and purchase new ones, (2) return the instrument and/or cable to the manufacturer for repair, or (3) have the manufacturer perform repair or replacement of connectors in the field using in-containment welding or brazing. Scrapping of the instruments and/or cables generates both high level and low level radioactive waste, and the purchase of new equipment is an unplanned expense for the utility. Returning the equipment to the manufacturer is not always feasible due to radioactive contamination. Because of the radioactive environment in which these connectors are used inside the containment structure of the nuclear reactor power plant and because of the equipment and time required, welding or brazing inside this containment is an expensive undertaking in terms of both monetary cost and radiation exposure to those performing the work. Accordingly none of these options are particularly attractive.